Purana Quila

Also known as Old Fort.
Humayun- The Mughal Emperor Costructed The Fort
When the second Mughal emperor Humayun decided
to make a city of his own he decided on the
site of the ancient city of Indraprastha. Humayun
was quite a scholar with a fine grasp on such
matters and so it is certain that the site was
chosen deliberately. When his Sher Shah Suri
overthrew him, he destroyed most of Dinpanah
(refuge of the faithful) as the city of Humayun
was called to make way for his own Dilli Sher
Shahi or Shergarh. Incidentally, Humayun was
probably the only emperor in history who built
a city in Delhi and did not give it his own
name  this was typical of Humayun's rather
sophisticated and dreamy character. The Layout
of The Massive Colossal.

Qila-i-Kuhna Mosque
he single-domed Qila-i-Kuna Mosque, built by
Sher Shah in 1541 is an excellent example of
a pre-Mughal design. The prayer hall inside
has five elegant arched niches or mihrabs set
in its western wall. Marble in shades of red,
white and slate is used for the calligraphic
inscriptions and marks a transition from Lodhi
to Mughal architecture. A second storey provided
space for female courtiers to pray, while the
arched doorway on the left wall, framed by ornate
jharokas, was reserved for members of the royal
family.

Sher Mandal
he Sher Mandal stands to the south of the mosque.
This double-storeyed octagonal tower of red
sandstone was built by Sher Shah and was used
as a library by Humayun after he recaptured
the fort. The tower is topped by an octagonal
chhatri supported by eight pillars and decorated
with white marble. Inside there are remnants
of the decorative plaster-work and traces of
stone-shelving where, presumably, the emperor's
books were placed. This was also the tragic
spot where, on 24 January, 1556 Humayun slipped
off the stairs, missed his footing and stumbled
to his death.